The present disclosure generally relates to communications within wireless mesh networks operating within a building automation system. In particular, the present disclosure relates to method and tool for communicating with sleeping wireless devices deployed within the building automation system.
A building automation system (BAS) typically integrates and controls elements and services within a structure such as the heating, ventilation and air conditioning (HVAC) system, security services, fire systems and the like. The integrated and controlled systems are arranged and organized into one or more field level networks (FLNS) containing application or process specific controllers, sensors, actuators or other devices distributed to define or establish a network. The field level networks provide general control for a particular floor or region of the structure. For example, a field level network may be an RS-485 compatible network that includes one or more controllers or application specific controllers configured to control the elements or services within floor or region. The controllers may, in turn, be configured to receive an input from a sensor or other device such as, for example, a room temperature sensor (RTS) deployed to monitor the floor or region. The input, reading or signal provided to the controller, in this example, may be a temperature indication representative of the physical temperature. The temperature indication can be utilized by a process control routine such as a proportional-integral control routine executed by the controller to drive or adjust a damper, heating element, cooling element or other actuator towards a predefined set-point.
Information such as the temperature indication, sensor readings and/or actuator positions provided to one or more controllers operating within a given field level network may, in turn, be communicated to an automation level network (ALN) or building level network (BLN) configured to, for example, execute control applications, routines or loops, coordinate time-based activity schedules, monitor priority based overrides or alarms and provide field level information to technicians. Building level networks and the included field level networks may, in turn, be integrated into an optional management level network (MLN) that provides a system for distributed access and processing to allow for remote supervision, remote control, statistical analysis and other higher level functionality. Examples and additional information related to BAS configuration and organization may be found in the co-pending U.S. patent application Ser. No. 11/590,157, filed on Oct. 31, 2006, and co-pending U.S. patent application Ser. No. 10/915,034, filed on Aug. 8, 2004, the contents of these applications are hereby incorporated by reference for all purposes.
Wireless devices, such as devices that comply with IEEE 802.15.4/ZigBee protocols, may be implemented within the control scheme of a building automation system without incurring additional wiring or installation costs. ZigBee-compliant devices such as full function devices (FFD) and reduced function devices (RFD) may be interconnected to provide a device net or mesh within the building automation system. For example, full function devices are designed with the processing power necessary to establish peer-to-peer connections with other full function devices and/or execute control routines specific to a floor or region of a field level network. Full function devices are typically line powered devices which are always awake and/or active and ready to communicate. Each of the full function devices may, in turn, communicate with one or more of the reduced function devices in a hub and spoke arrangement. Reduced function devices such as the temperature sensor described above are designed with limited processing power necessary to perform a specific task(s) and communicate information directly to the connected full function device. Reduced function devices are typically battery powered devices which remain asleep and/or inactive for extended periods of time to conserve battery power.